Make NotificationPublisher optional

Author: Bellangelo

src/Capability/Registry.php

@@ -60,7 +60,7 @@ class Registry
     private array $resourceTemplates = [];
 
     public function __construct(
-        private readonly NotificationPublisher $notificationPublisher,
+        private readonly NotificationPublisher $notificationPublisher = new NotificationPublisher(),
         private readonly ReferenceHandler $referenceHandler = new ReferenceHandler(),
         private readonly LoggerInterface $logger = new NullLogger(),
     ) {

tests/Capability/Discovery/DiscoveryTest.php

@@ -19,7 +19,6 @@
 use Mcp\Capability\Registry\ResourceReference;
 use Mcp\Capability\Registry\ResourceTemplateReference;
 use Mcp\Capability\Registry\ToolReference;
-use Mcp\Server\NotificationPublisher;
 use Mcp\Tests\Capability\Attribute\CompletionProviderFixture;
 use Mcp\Tests\Capability\Discovery\Fixtures\DiscoverableToolHandler;
 use Mcp\Tests\Capability\Discovery\Fixtures\InvocablePromptFixture;
@@ -35,7 +34,7 @@ class DiscoveryTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->registry = new Registry(new NotificationPublisher());
+        $this->registry = new Registry();
         $this->discoverer = new Discoverer($this->registry);
     }